Actin Polymerization State Regulates Osteogenic Differentiation in Human Adipose-derived Stem Cells

Background:Actin is an essential cellular protein that assembles into microfilaments and regulates numerous processes such as cell migration, maintenance of cell shape, and material transport. In this study, we explored the effect of actin polymerization state on the osteogenic differentiation of human adipose-derived stem cells (hASCs). Methods:The hASCs were treated with different concentrations (0, 1, 5, 10, 20, and 50 nM)of jasplakinolide (JAS), a reagent that directly polymerizes F-actin.The effects ofthe actin polymerization state on cell proliferation, apoptosis, migration, and the maturity of focal adhesion-related proteins were assessed. In addition, western blotting and alizarin red staining assays were performed to assess osteogenic differentiation. Results: These results revealed that cell proliferation and migration in the JAS (0, 1, 5, 10, and 20 nM) groupswashigher than that inthe control group andthe JAS (50 nM) group.The protein expressionof focal adhesion kinase, vinculin, paxillin, and talinwere highest in the JAS (20 nM) group, whilezyxin expression was highestinthe JAS (50 nM) group.Western blottingshowed thatosteogenic differentiation in theJAS (0, 1, 5, 10, 20, and 50 nM) groupswas enhanced compared with that in thecontrol group, and was strongest inthe JAS (50 nM) group.Conclusions: Our data suggest thatthe actinpolymerization state may promote the osteogenic differentiation of hASCs by regulating the protein expression of focal adhesion-associated proteins in a concentration-dependent manner. Our findings provide valuable information for exploring the mechanism of osteogenic differentiationin hASCs.